Asthma is the most common chronic disease in children, and asthma rates are even higher among inner-city children. The number of children with asthma and the seriousness of their disease is increasing. The purpose of this study is to evaluate the effectiveness of three interventions: 1) augmented usual care, to include physician education and regular computerized feedback, 2) coordinated care, to include clinic-based case management, and 3) coordinated care plus environmental modification. By doing this study we hope to learn new information that will improve the way we care for children with asthma. The primary outcome measure will be the number of symptom days in the preceding two weeks. Additional outcome measures will include unscheduled service use (hospitalization, emergency department visits, and acute clinic visits), forced expiratory volume in one second (FEVI), and quality of life. This is a cooperative study that includes six additional study sites besides Seattle. We plan to enroll 120 Seattle children ages four to twelve with moderate to severe asthma. We anticipate that this study will provide information regarding the relative effectiveness of the three interventions to be studied.